Abstract: In order to solve the problems of complicated trajectory, low efficiency of manual chamfering and unable to guarantee machining quality of spiral bevel gears in five-axis CNC machine tool due to two extra rotation axes, the tooth profile chamfering trajectory planning of spiral bevel gears was studied in this paper. Firstly, the tooth profile equation of spiral bevel gear is calculated, and the target discrete points of tooth profile are obtained after the accuracy of the equation is verified. Secondly, the coordinate transformation matrix is calculated according to the coordinate transformation principle, and the cutter axis vector is calculated according to the chamfering position of the ball-end cutter. Then, MATLAB and VERICUT chamfering simulation were carried out to analyze the chamfering results under different machining depths. Finally, the chamfering trajectory under the five-axis CNC machine tool is obtained. The cutting simulation results show that the machined surface is relatively uniform, which can realize the chamfering of the tooth profile on the CNC machine tool, replace the manual chamfering and improve the processing efficiency.